[Frank Lee]

I have considered such a beast before and decided that the engine(s) either need to be split from within a common block, or be close enough together to share coolant and oil so as to keep the "part-time" stuff hot for when it's called to action. Letting the part-time stuff go cold all the time would be bad.

Then there is the vibes problem, they really need to be indexed to each other somehow or very disagreeable vibes will result... I think.